Many health-conscious consumers adopt low-carb eating habits to lose weight and ward off heart disease and diabetes. But b careful-it can backfire. A low-carbohydrate, Atkins-style diet with lots of animal protein actually may increase your risk for type 2 diabetes.
Our study analyzed the medical records of 41,140 men (all free of heart disease, cancer and diabetes at the start) in the Health Professionals Follow-Up study. The participants completed questionnaires about their eating habits once every four years for more than 20 years, during which time 2,761 of the men developed type 2 diabetes.
After taking into account risk factors such as body mass index, physical activity, family history of diabetes, smoking, coffee and alcohol consumption and total caloric intake, we found that the men whose diets were lowest in carbohydrates (averaging 37% of calories) but high in animal protein (18% of calories) and animal fat (26% of calories) had a 41% higher risk for type 2 diabetes than men consuming a higher carbohydrates (57% of calories) diet where animal protein (10% of calories) and animal fat (12% of calories) were lower.
The findings are preliminary, based on an observational study, and further research is necessary.
What To Eat?
It isn't that low-carbohydrate, high-protein and high-fat diets are inherently harmful; it's the type of protein and fat you consume. The problem with animal sources of protein, especially red and processed meat, relates to their fat and iron content. Taking in lots of saturated fats (as found in these meats) can reduce insulin sensitivity. Additionally, iron can accumulate in body tissue, generating oxidative stress, insulin resistance and (if the iron accumulates in the pancreas) problems in secreting insulin.
Note: Iron is an important nutrient, and deficiency brings its own set of problems, so people who are anemic may be advised to eat meat. Red meat (beef, of course, but also lamb, pork and veal) is rich in heme iron, which is the most effective at reversing iron deficiency, since it is absorbed better than non heme. Moderation and balance are key.
A better way: The Nurses' Health Study (also from Harvard) found that eating greater quantities of vegetable proteins and vegetable fats as part of a low-carbohydrate diet was inversely associated with diabetes risk, said Dr. de Koning.
For most folks, the best high-protein, low carb diet includes very little red or processed meat, a smattering of chicken and fish, and lots of vegetable proteins (including legumes and nuts) and vegetable fats. Good protein sources include tofu (10.3 grams of protein per one-half cup)...black beans (15.2 grams or protein per cup)...roasted beets (3.9 grams of protein per one-half cup)...and almonds (6 grams of protein per quarter cup).
Eating a low-carb diet can be all-around healthy. It helps control your weight and, said Dr. de Koning, "may actually reduce your risk for chronic disease if your sources of fat and protein (what you replace the carbs with) are chosen carefully." That means that red meat should be ordered rarely...rather than rare, medium or well-done.
For more information on what to eat to stop diabetes, see Chapter 3, "Foods That Fight Diabetes."
